Table 4. Chemical constitutions of the original iron obtained with high purity pig iron and recarburized steel scrap at FAW Foundry Co. Ltd. (%) 表4 一汽铸造有限公司用高纯生铁和废钢增碳工艺获得的原铁液化学成分（%）
C
High purity pig iron 高纯生铁
Recarburized steel scrap 废钢增碳
3.67 3.9 Si 1.84 1.90 Mn 0.12 0.24 P 0.017 0.021 S 0.008 0.003 Cu 0.7 0.67 Mo 0.22 0.18 Cr 0.051 0.023 Ti 0.008
burized high grade steel scrap has been widely used in China. Recently, FAW Foundry Co. Ltd., Jilin, China, and its business partners obtained original molten ductile iron by adopting high purity pig iron and recarburized steel scrap in the development of an ADI crankshaft for a 1.8T Besturn supercharger engine (Table 4). In order to meet the yield and quality requirements
of cast ductile iron in both domestic and international markets, enterprises have adopted advanced processes and equipment when building new plants and retrofitted old plants. In 2008, the ductile iron yield in China reached 8
million tons, which accounts for one third of the world’s production. Structural ADI components reached more than 900,000 tons.
Progress Made in CADI and ADI Parts ADI has high abrasion resistance and toughness, and
carbidic austempered ductile iron (CADI) has high hard- ness and wear resistance, making the materials attractive for use in wear parts in mining, engineering and agricul- ture machinery. Many domestic factories have launched research work to cast ADI and CADI parts such as a coal conveyer scraper, grinding balls and a coal pulver- izer motherboard. In Europe, mining and engineering machinery make up 22% of the ADI market, ranking second only to the automobile industry. In the U.K., ADI has been used to make racks and bevel gears converted from forged steel in a light excavator for JCB Ltd., Rocester, U.K. The rack weighs 7 kg and measures 90 × 275 mm, and the bevel gear weighs 8 kg and measures 140 × 210 mm. The ADI parts were machined before heat treatment. The hardness of these materials is about 55-60 Rockwell hardness after heat treatment. Convert- ing to the net-shape castings reduced machining allow- ances and omitted the quenching, tempering and shot peening processes. Moreover, the service life was prolonged and maintenance cost reduced compared to forged steel. Hebei Qianxi Aodiai
Mechanical Casting Co. Ltd.,
碳工艺也能生产这种优质铁液。废钢增碳生产工艺在国 内应用已很成熟。最近一汽集团铸造有限公司和有关合 作单位共同开发1.8T奔腾轿车增压发动机ADI曲轴时， 球墨铸铁曲轴原铁液同时采用高纯生铁和废钢增碳两种 工艺获得，其成分如表4。可见两种金属炉料均能获得 合乎要求的成分。
2）为了满足国内外对球墨铸铁件产量和质量的要 求，采用先进的工艺装备和技术建设新厂和对旧厂进行 技术改造。
目前，我国球墨铸铁件年产5000吨以上，生产设备 较先进、质量较稳定的厂已达80家以上（不包括铸管 厂）。它们一般采用冲天炉—电炉双联或直接用中频炉 熔炼，配有炉前碳当量测定仪和真空直读光谱仪，比较 重视原铁液质量。部分厂采用气动、搅拌、摇包脱硫工 艺以获得高温（>1500℃）低硫（<0.02%）低氧化的 原铁液。
铸型多用高紧实度粘土砂机械化造型，如静压、高 压、挤压等，以及金属型、壳型填铁丸、金属型覆砂、 树脂砂等，以保证铸型刚度，利用球墨铸铁糊状凝固及 石墨化膨胀的特点，解决铸件缩松问题。 球化剂、孕育剂均有专业生产厂供应，可根据不同球 墨铸铁件的具体要求提供相应成分、粒度的产品；球化 处理方法除冲入法外，盖包、转包、喂线、喷射等方法 都在应用，倒包孕育、随流孕育、型内孕育等先进孕育 工艺都得到广泛应用，可以说我国已具备稳定生产高质 量球墨铸铁件的基本条件。2008年，我国球墨铸铁产 量已达800多万吨，占世界球墨铸铁产量1/3以上，其 中优质工程结构球铁件约90万吨以上，它们都能满足生
产ADI铸件的要求。
CADI磨球和ADI衬板的应用取得明显效果 ADI有很好的抗磨、耐磨性能，又有较好的韧 性；CADI（carbide austem- pered ductile iron-含碳化物 奥铁体球墨铸铁）具有较高 的硬度（HRC>56）和抗磨性 能，在冶金矿山、煤矿机械、 工程机械、农业机械等抗磨、 耐磨构件领域中有很好的应用
Shown is ADI heat treatment equip- ment from Jiashan, Zhejiang Yong EAF Industry Co. Ltd.
图1 浙江嘉善三永电炉工业有限公 司的ADI热处理设备 。
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FOUNDRY-PLANET.COM | MODERN CASTING | CHINA FOUNDRY ASSOCIATION Spring 2012
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